feat(P02): l1-lambda manifest + mock_apply (T-2.3)

---ci---
phase: 2
milestone: v1.0
status: execute
persona: infra-stub-engineer
task: T-2.3
requirements:
  covered: [REQ-02, REQ-03]
---/ci---

Wave 1, task T-2.3. Creates modules/l1/l1-lambda/ with manifest.yaml
(flat inputs per D-017) and the uniform mock_apply.sh (D-007 + D-018).

modules/l1/l1-lambda/manifest.yaml

@@ -0,0 +1,13 @@
+name: l1-lambda
+kind: l1
+description: Event-driven function primitive
+inputs:
+  function_name:
+    description: Name of the Lambda function
+    type: string
+  runtime:
+    description: Lambda runtime identifier (e.g. python3.12, nodejs20.x)
+    type: string
+  handler:
+    description: Handler entrypoint in the form module.function
+    type: string

modules/l1/l1-lambda/mock_apply.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+set -euo pipefail
+echo "[L1: l1-lambda] applying..."
+sleep 1
+echo "[L1: l1-lambda] OK"
+exit 0